Comment 7 for bug 2018318

Dear OpenStack Compute (nova) Code Maintainer(s),

I hope this message finds you well.

The current behavior, when migrating or flavor resizing VMs that were created without an explicit availability zone (AZ), leads to the following problems:

    1) Despite having the 'cinder_cross_az_attach' configuration set to 'false', cross-AZ attached Cinder volumes still occur.
        This results in volume-based VMs being restarted in the incorrect AZ, leading to degraded disk latency.

    2) Image-based VMs come to a halt and become stuck in an error status.
        This is because their Ceph RBD images cannot be found in the Nova pool of the wrong AZ.
        Recovering such VMs involves administrator intervention and changing the database directly.

We have received multiple customer tickets related to this issue, wherein they have uploaded images, created VMs, and encountered difficulties when attempting to resize them.

By ensuring that the 'cinder_cross_az_attach' configuration is honored during migration or resizing, we can significantly improve user experience and reduce related issues.

We kindly request you to review and consider merging the proposed bug fix into the upstream code.

Thank you for your time and attention to this matter. We believe that this fix will greatly benefit the OpenStack Nova community.

Best regards,
Francois Scheurer